matplotlib笔记四：绘制鸢尾花数据散点图

Posted 2022-11-19 周虽旧邦其命维新

使用matplotlib绘制鸢尾花数据散点图：

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
from sklearn import datasets

iris = datasets.load_iris()
# print(iris, type(iris))
print(iris.keys())
# print(iris.DESCR)
# print(iris.data)
# print(type(iris.data))
# print(iris.data.shape)
# print(iris.feature_names)
# print(iris.target)
# print(iris.target.shape)
print(iris.target_names)
x = iris.data[:, :2]
# print(x.shape)
# plt.scatter(x[:,0], x[:,1])
# print(x, type(x), x.shape)
y = iris.target
# print(y.shape, y==0)
# print(x[y==0], type(x[y==0]))
plt.scatter(x[y==0,0], x[y==0,1], color='red')
plt.scatter(x[y==1,0], x[y==1,1], color='blue')
plt.scatter(x[y==2,0], x[y==2,1], color='yellow')
# x是一个150行2列的二维数组，y==0得到每一行target是否等于0的包含150个元素的布尔类型数组
# x[y==0,0]通过numpy矩阵索引的方式取出target为0的所有行的第0列

# x = iris.data
# plt.scatter(x[y==0,2], x[y==0,3], color='red')
# plt.scatter(x[y==1,2], x[y==1,3], color='blue')
# plt.scatter(x[y==2,2], x[y==2,3], color='yellow')

plt.show()